Story Highlights

Imagine this scenario: You're at a party and you've had a couple of cocktails and you don't want to make that 45-minute journey home.

Or you're on a road trip, and you just need a few hours of sleep before you make that final push to your destination.

Or maybe you're on a business trip and your work is not yet done. So you've got to spend one more night in town and the hotel you were at is sold out.

There are all sorts of reasons that force travelers to book a hotel room at the last minute. It used to be that you'd have to pick up your phone and call several hotels to see if they had a room in your price range.

Now, there are a number of mobile apps that either specialize in last-minute hotel bookings or have sections that do.

According to market research company PhoCusWright, 18% of online sales at hotels this year -- or $7.5 billion -- will come from Smartphone and tablets on websites and apps. More than half of all phone bookings are made the same day.

Priceline(Free, available on Android, iOS, Windows Phone)Priceline is best known as a hotel bidding site. You name your price and desired star rating of the hotel, and you book the room without knowing the name of the hotel. First you choose the location and the star level, and then you enter your bid. I asked for a five-star hotel in Downtown D.C. near the White House. The median retail price for that kind of hotel, I was told, was $351. If I didn't want to bid on a room, I could opt for an "Express Deal" instead for a similar hotel for $282 but I'd have to be comfortable with finding out the name of the hotel after booking. I decided to place a bid for $250. I got a room for a total of $296.81 with taxes and fees. But I would not find out the name of the hotel until I typed in my credit card number. If I didn't feel comfortable with that, I could browse the day's dozens of available hotel rooms, organized by proximity to where I was. The closest hotel to me, 0.4 miles away, was the four-star Omni Shoreham at $289. It had a guest score of 9.1 out of 10. The score, based on 132 reviews, was broken down into cleanliness, dining, staff and location. A photo gallery and list of amenities were also available.

Expedia(Free, available on Android, iOS)The app has a dedicated "Tonight" section. The first of dozens of options that were listed by proximity to me was the Windsor Inn, 0.7 miles away, for $129. I could sort the list of hotels by popularity, price, deals, rating and distance. Within the list, there were many rooms discounted for "tonight only." The Embassy Row Hotel, for instance, was on sale for tonight only for $127, a 20% discount. When I sorted the hotel by distance, The Quincy hotel showed up at the top of the list as 0 miles away. The Quincy was actually not the closest hotel to my location. Neither was the Mayflower Renaissance, which also appeared as 0 miles away. But I did find the Omni Shoreham, for $269, less than its Priceline pricetag. When I clicked on the Omni Shoreham, there were icons showing me which amenities were available. I was also told that 94% of guests recommended it, and that it was based on 1,564 reviews. There was a map and detailed information about policies and fees.

Orbitz(Free, available on Android, iOS, Windows Phone, Blackberry)When I clicked on the "Nearby & Available Tonight" section, dozens of choices came up. The Omni Shoreham appeared as a four-star hotel with a 4.2 out of 5 guest score and a pricetag of $289. When I clicked on it, I was actually told which room type I'd get: a Deluxe room with two double beds. I could click on "see all room types" to find out which other room types I could get for that price. What set Orbitz apart from the other apps was its elaborate guest reviews section. You can find out how the hotel fared with business travelers, couples, families, friends and singles, and how many of each gave their input. The guest score was based on room cleanliness, hotel staff, room comfort, location and value. You have the option of seeing reviews only by verified customers, and you can read them in English or Spanish. Head back to the search results, and you can sort the hotels by best bets nearby, lowest price, distance, star rating and hotel name. Narrow down your list even more by filtering the choices by amenities, areas, hotel chains, star rating and reviewer score.

Travelocity(Free, available on Android, iOS, Windows Phone)I clicked on the "Deals Tonight" section and got 125 results. I could sort the list by Travelocity Picks, prices, distance, ratings or alphabetical names. I could filter by searching for a particular hotel, star ratings, user ratings and amenities. The Omni Shoreham showed up as a four-star hotel with a guest score of 4.9 out of five based on 105 reviews. Pricetag: $269 for a deluxe room with a queen bed. I could browse photos and a list of amenities. If that price was too steep, I could go for a "Top Secret" hotel for up to 45% off per night. There was a four-star hotel near the US Capitol with a three out of five-star user rating for $114. I was told that hotels in the four-star category may include Hilton, Hyatt or Westin, but I wouldn't know which one until I booked.

JetSetter(Free, available on iOS)Jetsetter bills itself as a community of travelers that provides expert knowledge and exclusive deals on vacations. Its mobile app has a Jetsetter Now feature, which allows you to book same-night hotel stays for up to 60% off. Jetsetter says one of its correspondents has "personally visited and reviewed every experience." Unlike the other apps, Jetsetter only offers deals in seven cities: New York, Miami, Boston, Chicago, Las Vegas, San Francisco and Los Angeles. I clicked on Las Vegas and was told deals would appear at 3 p.m. EDT. I could get a notification once the deals were available. Deals for New York, Miami and Boston were live, however. So I clicked on New York and got four options. One of them was a "Downtown Contemporary" hotel for $210, down from $349. There were just five rooms left in that category. When I clicked on it, it said that 92% of guests from 368 stays would recommend it to a friend. Under the Review section, there was a list called "What We Love," which included that it is "crammed with new-wave restaurants, homegrown boutiques, speakeasy-style cocktail bars and pumping music venues." Under "What to Know," it said I'd be e-mailed the name of the hotel as soon as I booked it.

Hotel Tonight(Free, available on Android, iOS)Daily deals don't go live until noon local time. At noon, my iPhone beeped to say that today's deals were ready. I got 16 options in D.C., Maryland and Virginia. Kimpton's Topaz Hotel in D.C. was on sale for $95, down from $219. Of 35 ratings, 94% gave it a thumps up. Hotel Tonight categorizes hotels as hip, luxe, solid, basic, charming or appropriate for high rollers. Click on the hotel, and you get a list of amenities, such as Wi-Fi and breakfast. There's a "Why We Like It" section. One reason Topaz was liked is that it has a "mélange of coolly striped walls, funky patterns and vibrant shades of purple." One drawback: You won't get a guarantee on a specific room or bed type until check-in. But you definitely get one of the steepest discounts of any of the apps.